How can I mock the ConstraintValidatorContext? It can't be null because I am using it to keep track of the errors for the custom validation annotation. I tried to #Autowired, #InjectMocks, and create an instance of it (but it's an interface, so not possible). Right now, I'm getting a null pointer.
Junit
#Test
public void isValid(){
Pokemon value = new Pokemon();
// assume mock for logic
ConstraintValidatorContext context = mock(ConstraintValidatorContext .class);
ConstraintValidatorContext.ConstraintValidatorBuilder builder =
mock(ConstraintValidatorContext.ConstraintValidatorBuilder.class);
when(context.getDefaultConstraintMessageTemplate()).thenReturn("");
when(context.buildConstraintViolationWithTemplate(anyString())).thenReturn(builder);
when(builder.addPropertyNode("artistBean.name")).thenReturn(any(NodeBuilderCustomizableContext.class));
when(builder.addConstraintViolation()).thenReturn(context);
assertTrue(validator.isValid(value, context));
}
Validator
public boolean isValid(){
boolean isValid;
// assume logic
// adding validation error; how to mock below?
context.buildConstraintViolationWithTemplate(context.getDefaultConstraintMessageTemplate())
.addPropertyNode("artistBean.name").addConstraintViolation();
return isValid;
}
Related
I am not sure how to test the first method in the service layer with Mockito as it is using the helper method. Below is my failed attempt at a test: I get an InvalidUseOfMatchersException in the second when clause.
Thanks in advance!
#Mock
private EntityRepository EntityRepo;
#InjectMocks
private EntityService EntityService;
public List<DTO> getAllDTOs(){
//first method
return entityRepo.findAll()
.stream()
.map(this::convertEntityToDTO)
.collect(Collectors.toList());
}
//helper method
public DTO convertEntityToDTO(Entity entity) {
ModelMapper modelMapper = new ModelMapper();
modelMapper.getConfiguration()
.setMatchingStrategy(MatchingStrategies.LOOSE);
DTO dto = new DTO();
dto = modelMapper.map(entity, DTO.class);
return dto;
}
#Test
public void EntityService_GetAll_ReturnsDTOList() {
when(entityRepo.findAll()).thenReturn(Mockito.anyList());
//the second when clause: when(entityService.convertEntityToDTO(Mockito.any(Entity.class)))
.thenReturn(Mockito.any(DTO.class));
List<DTO>DTOList = entityService.getAllDTOs();
Assertions.assertThat(DTOList).isNotNull();
Mockito#any* methods are actually defined in class ArgumentMatchers and can only be used to match the call arguments when setting up a mock or when verifying calls. All matcher methods return null (but have side-effects of modifying a matcher stack to be able to properly detect and match mocked calls).
For instance, you might do Mockito.when(svc.print(Mockito.anyString()).doNothing() when you don't care about the input or Mockito.verify(svc.print(Mockito.anyString()), Mockito.never()) when you want to verify that the method has never been called.
When setting up your mock, you have to provide a real value in your thenReturn call:
when(entityRepo.findAll()).thenReturn(Collections.emptyList());
when(entityService.convertEntityToDTO(Mockito.any(Entity.class)))
.thenReturn(new DTO());
I have my onw annotation:
#Constraint(validatedBy = {MaxDateValidator.class})
#Target({METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER})
#Retention(RetentionPolicy.RUNTIME)
public #interface MaxDate {
and my validator:
#RequiredArgsConstructor
public class MaxDateValidator implements ConstraintValidator<MaxDate, LocalDate> {
#Override
public void initialize(MaxDate constraintAnnotation) {
...
}
#Override
public boolean isValid(LocalDate date, ConstraintValidatorContext constraintValidatorContext) {
//I want to throw my onw exception here with some hint to be read by
frontend
if(condition){
throw new MyException("message", HINTS.WRONG_DATE);
}
return someCondition();
}
}
My question is if it's possible to throw my own exception in isValid method? I have my own annotation #MaxDate set on some field in my Dto coming from frontend and in some cases I'd like to throw here my own exception with some hint to be read by frontend and displaying some validation message.
Or maybe I should completely remove this annotation and do some validation in my service method?
It's not a good idea to throw your own exception from the isValid method because by the contract this method shouldn't throw any exceptions (and should be threadsafe by the way). To customize the exception thrown by this validator you can use standard mechanisms like:
Add String message() default "your message"; field inside MaxDate annotation.
Use ConstraintValidatorContext like this:
if(condition){
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate("Your message").addConstraintViolation();
return false;
}
I have a use case where it would be extraordinarily nice to dynamically instantiate beans (using some kind of factory approach) based on annotation-arguments at the injection point. Specifically, I need to be able to specify a type-argument to the bean-creating factory.
A pretty relevant example would be a JSON deserializer that needs the type which it needs to deserialize to.
I envision either:
#Inject
#DeserializeQualifier(Car.class)
private Deserializer<Car> _carDeserializer;
#Inject
#DeserializeQualifier(Bus.class)
private Deserializer<Bus> _busDeserializer;
.. or simply, if it was possible to sniff the type from the generic type argument:
#Inject
private Deserializer<Car> _carDeserializer;
#Inject
private Deserializer<Bus> _busDeserializer;
The big point here is that I would not know beforehand which types was needed in the project, as this would be a generic tool that many projects would include. So you would annotate your #Configuration class with #EnableDeserializer and could then inject any type deserializer (The factory that makes these deserializers can handle any type, but to be able create one, it would need to know the desired type of the deserialized object - plain generics would not cut it, since Java ain't using reified generics).
So, I'd need to be able to inject into the spring context, or using any other Spring magic tricks, some kind of DeserializerFactory that takes the type argument.
Basically, I need to have Spring invoke the following method based based on either, as in the first example, the qualifier argument (or the entire DeserializeQualifier-instance for that matter), or as in the second example, the generic type argument:
DeserializerFactory {
<T> Deserializer<T> createDeserializer(Class<T> type) { ... }
}
You could create a BeanFactoryPostProcessor to set attributes annotated with a custom annotation. I've set up a small Spring Boot project to play around:
// Custom annotation
#Target(ElementType.FIELD)
#Retention(RetentionPolicy.RUNTIME)
public #interface InjectSomeClassHere {
Class value();
}
// Demo bean
#Component
public class SomeBean {
#InjectSomeClassHere(String.class)
private Class someValue;
public Class getInjectedClass() {
return someValue;
}
}
// The BeanFactoryPostProcessor
#Component
public class SomeBeanFactoryPostProcessor implements BeanFactoryPostProcessor {
#Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
Arrays
.stream(beanFactory.getBeanDefinitionNames())
.filter(beanName -> hasAnnotatedField(beanFactory, beanName))
.forEach(beanName -> {
Object bean = beanFactory.getBean(beanName);
Stream.of(bean.getClass().getDeclaredFields()).forEach(field -> setFieldValue(bean, field));
});
}
private boolean hasAnnotatedField(ConfigurableListableBeanFactory beanFactory, String beanName) {
try {
String className = beanFactory.getBeanDefinition(beanName).getBeanClassName();
if (className == null) {
return false;
}
return Arrays.stream(Class.forName(className).getDeclaredFields())
.anyMatch(field -> field.isAnnotationPresent(InjectSomeClassHere.class));
} catch (ClassNotFoundException e) {
// Error handling here
return false;
}
}
private void setFieldValue(Object filteredBean, Field field) {
try {
// Note: field.isAccessible() is deprecated
if (!field.isAccessible()) {
field.setAccessible(true);
}
// Retrieve the value from the annotation and set the field
// In your case, you could call `createDeserializer(fieldValue);` and set the field using the return value.
// Note that you should change the type of `SomeBean#someValue` accordingly.
Class fieldValue = field.getAnnotation(InjectSomeClassHere.class).value();
field.set(filteredBean, fieldValue);
} catch (IllegalAccessException e) {
// Error handling here
e.printStackTrace();
}
}
}
// A small test to verify the outcome of the BeanFactoryPostProcessor
#RunWith(SpringRunner.class)
#SpringBootTest
public class SomeBeanTests {
#Autowired
private SomeBean someBean;
#Test
public void getInjectedClass_shouldHaveStringClassInjected() {
Assert.assertEquals(String.class, someBean.getInjectedClass());
}
}
Please note that this is a very naive implementation and requires further fine tuning. For instance, it scans all attributes in all spring components for the presence of an annotation.
Good luck with your project!
I want to pass org.springframework.validation.Errors to CodeValidator class.
But, since I am not using RequestBody/RequestPart/ModelAttribute, I cannot put Errors in method param after variable.
I use #RequestParam for code variable, and I want to validate that using CodeValidator class that implement org.springframework.validation.Validator.
Here is my code
#RequestMapping(value = "/check-code", method = RequestMethod.POST)
public ResponseEntity<Object> checkCode(#RequestParam("code") String code, Errors errors) {
codeValidator.validate(code, errors);
if(errors.hasErrors()) {
return ResponseEntity.badRequest().body("Errors");
}
return ResponseEntity.ok("");
}
and here error result for my code:
An Errors/BindingResult argument is expected to be declared immediately after the model attribute, the #RequestBody or the #RequestPart arguments to which they apply: public org.springframework.http.ResponseEntity com.example.myapp.controller.CodeController.checkCode(java.lang.String,org.springframework.validation.BindingResult)
what should I do to be able using CodeValidator with #RequestParam?
Updated:
Code for CodeValidator
#Service
public class CodeValidator implements Validator {
#Override
public void validate(Object target, Errors errors) {
String code = ((String) target);
if(code == null || code.isEmpty()) {
errors.rejectValue("code", "", "Please fill in Code.");
}
}
}
Did you create an annotation with your validator?
Otherwise take a look at a small example/tutorial for custom validating with spring: https://www.baeldung.com/spring-mvc-custom-validator
(edit) if you are using spring boot you might need add a MethodValidationPostProcessor bean to your spring config to enable custom valdation for the #requesParam
I have a REST service written with Jersey & Spring-Boot. I have written custom validator classes for POST params. I want to unittest the same. I could not figure out how to do it. My Validator looks like below:
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = ValidTaskForCreate.Validator.class)
public #interface ValidTaskForCreate {
String message() default "Invalid Request to create a Task";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
public class Validator implements ConstraintValidator<ValidTaskForCreate, Task> {
#Override
public void initialize(ValidTaskForCreate constraintAnnotation) {
}
#Override
public boolean isValid(final Task task, ConstraintValidatorContext context) {
context.disableDefaultConstraintViolation();
if(task.getName() == null || task.getName().isEmpty()) {
context.buildConstraintViolationWithTemplate("Task name should be specified").addConstraintViolation();
return false;
}
if(task.getTaskType() == null) {
context.buildConstraintViolationWithTemplate("Specify a valid TaskType in the range of [1..3]").addConstraintViolation();
return false;
}
return true;
}
}
}
Now i want to test the isValid() function by passing various Task objects. I am not sure how to call this method now.
I can create instance of Validator class like this,
ValidTaskForCreate.Validator taskValidator = null;
taskValidator = new ValidTaskForCreate.Validator();
To call isValid(), i can use taskValidator.isValid(). But i do not know how to create the ConstraintValidatorContext object to pass as 2nd parameter.
Or is there any way to UnitTest custom validations classes like this?
But i do not know how to create the ConstraintValidatorContext object to pass as 2nd parameter.
Just use Mockito and mock it. Then just verify that the correct methods were called. This is how to test the behavior of the unit when dependencies are involved.
private ConstraintValidatorContext context;
private ConstraintValidatorContext.ConstraintViolationBuilder builder;
#Before
public void setup() {
// mock the context
context = Mockito.mock(ConstraintValidatorContext.class);
// context.buildConstraintViolationWithTemplate returns
// ConstraintValidatorContext.ConstraintViolationBuilder
// so we mock that too as you will be calling one of it's methods
builder = Mockito.mock(ConstraintValidatorContext.ConstraintViolationBuilder.class);
// when the context.buildConstraintViolationWithTemplate is called,
// the mock should return the builder.
Mockito.when(context.buildConstraintViolationWithTemplate(Mockito.anyString()))
.thenReturn(builder);
}
#Test
public void test() {
// call the unit to be tested
boolean result = ..isValid(badTask, context);
// assert the result
assertThat(result).isFalse();
// verify that the context is called with the correct argument
Mockito.verify(context)
.buildConstraintViolationWithTemplate("Task name should be specified");
}
Note the use of Mockito directly. In most cases you will probably just use static imports to make it less verbose. I just wanted to make it more readable
This is the best way I found using standard Spring unit testing with no need to mock anything.
#RunWith(SpringRunner.class)
#SpringBootTest(classes= {ValidationAutoConfiguration.class})
public class AllowedValuesValidatorTest {
#Autowired
private Validator validator;
#Test
public void testIsValid() {
ObjectToBeValidated obj = // create object
Set<ConstraintViolation<ObjectToBeValidated>> violations = validator.validate(obj);
boolean violationsFound =
violations.stream().anyMatch(v -> v.getConstraintDescriptor().getAnnotation().annotationType().equals(
NonNullLowercaseLettersOrNumbersOnly.class));
assertThat(externalIdViolationFound).isTrue();
}
}
It's the ValidationAutoConfiguration.class as the configuration of the test that does the heavy lifting. This will exercise all validation on the ObjectToBeValidated and you can search the violations for just that one you're testing for.